Various conventional keying arrangements utilize keying projections on one of a pair of matable connector housings which are received into corresponding keying grooves or channels of the other of the housings. Such keying arrangements permit mating of the appropriate corresponding connectors while preventing the mating of similar appearing connectors which are not intended to be mated. Certain prior art connectors include keying projections which are fabricated integrally with the housing at preselected locations, which necessitates manufacture of a plurality of housings different only in their particular keying projection arrangements. Other prior art connectors are first fabricated without keying projections, and separate key members are secured at desired locations in a further procedure, requiring the handling of many pieces and the time and labor of an operator to insure that the proper keying arrangement is incorporated.
Several connectors have incorporated programmable keying members therein. As shown in U.S. Pat. No. 4,832,625, plug and receptacle connector housings are molded with a plurality of deflectable members proximate their mating faces along housing side walls which become adjacent each other upon connector mating. The deflectable members are joined to respective housing side walls so that the deflectable members are deflectable thereinto if desired, enabling customizing of the connector housing to provide a system of keying particular plug housings with particular receptacle housings. Although this type of keying arrangement does not require additional pieces to be used, the operator must program the deflectable keying members prior to mating the plug with the receptacle. The programming of the members is time consuming, and can be particularly difficult if the connector halves are positioned in an environment in which space is at a premium.
It would therefore be advantageous to provide a programmable keying system in which the programming of the keying occurred automatically as the connector halves were mated together. This would eliminate the input from the operator, and insure for the reliability of the keying system.